Muscular movement involves nerves controlling muscles with electrical signals called impulses. Electromyography (“EMG”) involves the testing of the electrical activity of muscles at rest and when contracted. EMG specifically measures muscle response or electrical activity in response to a nerve's simulation of the muscle.
An EMG needle is used to perform an intramuscular EMG procedure. An EMG needle includes a cylindrical electrode having an elongated body. The elongated body of the electrode includes a distal end or tip portion (which defines a pointed or sharpened tip), a middle unsharpened, non-tip portion and an unsharpened proximal end or handle connecting portion. The EMG needle includes a handle, such as a molded plastic handle or hub, connected at or to the proximal end or handle connecting portion of the elongated body of the electrode (i.e., opposite the distal end or tip portion of the elongated body of the electrode). The electrode is electrically connected to an electric signal measuring and recording instrument, such as an electromyograph, to measure, record and display the electrical activity of the muscle tissue.
The EMG needle is typically either a monopolar EMG needle or a concentric EMG needle. A monopolar EMG needle is made of metal, such as stainless steel, wherein the whole needle, except for the tip or distal end, is coated with an electrically insulating material, such as polytetrafluorethylene (PTFE). The tip is sharpened to a conical shape and functions as the conductive receptor area (i.e., the electrical activity reception area) of the monopolar EMG needle. A concentric EMG needle includes a cannula and a core (made of different metals), wherein the tip of the concentric EMG needle has a flat elliptical shape. The core is embedded in an electrically insulating material such that the two metal parts of the concentric EMG needle are electrically insulated.
To perform an intramuscular EMG procedure, a medical professional cleans the skin over the area being tested. Following this cleaning, the medical professional inserts part of the electrode of the EMG needle (and specifically at least the sharpened tip portion of the electrode) through the skin and into the muscle tissue. Once inserted into the muscle tissue, the EMG needle (in conjunction with the electric signal measuring and recording instrument) detects the electrical current generated by the muscle cells when the muscle cells are at rest, when the muscle cells are slightly contracted and when the muscle cells are fully or forcefully contracted. This process is repeated several times for different areas of a muscle or for different muscles.
By analyzing the detected electrical current generated by the muscle cells at rest and during different levels of contraction, the medical professional can determine any irregularities in the patient's muscle activity. For example, by analyzing the detected electrical current generated by muscle cells, a medical professional may diagnose diseases that damage muscle tissue, nerves or where nerve and muscle join and/or determine the cause of weakness, paralysis, involuntary muscle twitching or other symptoms.
One potential issue associated with EMG needles is the sterilization or cleanliness of the electrode as the electrode contacts tissue and other parts of the body. Any tissue buildup on the electrode creates an environment where bacteria, biopathogens and other harmful organisms may cultivate and be introduced into the body during the EMG procedure. Furthermore, any gaps between the electrode and the handle/hub enables bacteria, biopathogens and other harmful organisms to get underneath the handle. This further promotes the growth of the bacteria, biopathogens and other harmful organisms which may migrate to the surface of the electrode or to the patient.
Additionally, if the sterilization of the EMG needle is not performed properly, not performed routinely, is consistently interrupted and resumed or not performed at all, bacteria, biopathogens and other harmful organisms can adhere to and grow on the surface of the electrode and then enter a patient's body during the EMG procedure. Moreover, if an EMG needle is reused on the same patient (or used on a different patient), bacteria, biopathogens and other harmful organisms can adhere to and grow on the surface of the electrode and then enter the patient's body when the EMG needle is reused during another EMG procedure. Such entering of bacteria, biopathogens and other harmful organisms into a patient's body can cause significant difficulties and complications for the patient after the EMG procedure is complete. As a result, minimizing the growth of bacteria, biopathogens and other harmful organisms on the surface of the electrode of the EMG needle is needed.